Effects of felodipine and metoprolol on blood pressure, plasma renin, angiotensin II, aldosterone and catecholamines in hypertensive patients.

Oral administration of felodipine to 10 patients with mild essential hypertension acutely reduced the brachial artery pressure by 15/13mm Hg. The tachycardia which occurred was sustained for 90 minutes together with an elevated plasma noradrenaline concentration. Addition of intravascular metoprolol after 90 minutes decreased heart rate. The felodipine-induced increase of plasma renin activity (100%; p less than 0.001) was completely reversed by metoprolol. Plasma angiotensin II (PA II) rose by 15% (p less than 0.05) during felodipine, whereas plasma aldosterone concentration was not significantly affected.